Serum exosome-encapsulated microRNAs as circulating biomarkers for breast cancer (360G-Wellcome-202418_Z_16_Z)

Key Goal : Investigation of Clinical Relevance of Exosome-encapsulated microRNAs (ExomiRs) in Circulation of Breast Cancer Patients MicroRNAs(miRNAs) are small non-coding RNA molecules known to regulate gene expression at a posttranscriptional level. In cancer, they play a pivotal role as either oncomirs or tumour suppressors, and are also detectable in the circulation, raising their potential as biomarkers of disease. miRNAs are now known to be secreted by cells, and recent studies have shown that this involves encapsulation into exosomes. The majority of miRNAs in whole blood are likely not reflective of the disease due to the confounding factors present. Recent studies support the fact that exosomes are reflective of their cells of origin, but this has not been investigated in any depth on a miRNA level. If the miRNA signature of exosomes (ExomiRs) were also reflective of the cell of origin, this could have important implications in their use as biomarkers, and potential indicators of tumour phenotype. The Discipline of Surgery Biobank currently contains > 1200 serum samples, from which exosomes can be isolated. This is an invaluable resource and is linked to complete clinicopathological, and treatment details of patients. ExomiRs may represent robust biomarkers reflective of tumour characteristics.